One of the key elements that QA folks would require while running test cases in Appium is to have a screenshot when a test case fails.
This would reduce their debugging time drastically.
If you are using Robot Framework & installed appium library, thankfully then this critical functionality comes by default.
Check the below screenshot, this would give an idea as to what was happening when a test case failed.
Not just during the time of failure, if you want screenshot at any point while running the test case, there is a useful keyword you can use in Robot Framework.
Capture Page Screenshot
Also if you are wondering how to have a structure for your appium test cases, check this blog.